William eats at a cafe and the cost of his meal is $\$29.00$. He would like to leave a $20\%$ tip. What is his total bill including tip?
Solution: The tip amount is equal to $20\% \times \$29.00$ We can find the tip by first calculating a $10\%$ tip and then multiplying that number by two. To calculate a $10\%$ tip, move the decimal point in $\$29.00$ one place to the left. $10\%$ $\times \$29.00$ $\$2.90$ To calculate a $20\%$ tip, multiply the $10\%$ tip amount by two. $20\%$ $\times \$29.00$ $\$2.90$ $ \times 2 = $ $\$5.80$ The cost of the meal plus the amount of the tip will equal the total bill amount. $\$29.00 + \$5.80 = $ $\$34.80$ The total cost of the bill is $\$34.80$.